Load lifting devices



April 26, 1966 c. s. cocKl-:RELL 3,248,086

LOAD LIFTING DEVICES Filed Jan. 4, 1963 3 Sheets-Sheet 2 INI/wrok C. 5. COC KERELL A T TOPNE YS April 26,v 1966 C, s, CQCKERELL 3,248,086

LOAD LIFTING DEVICES Filed Jan. 4, 1963 3 Sheets-Sheet 3 f. ////)V//77/// f //77 777 INVENTK C. 5. COCKERELL Cna/mman, @n/m .AT TURA/EYS United States Patent O 3,248,086 LOAD LIFTING DEVICES Christopher' Sydney Cockerell, Southampton, England,

assigner to Hovercraft Development Limited, London,

England, a British company Filed Jan. 4, 1963, Ser. No. 249,400 Claims priority, application /Great Britain, Jan. 9, 1962,

6 Claims. (Cl. 254-93) This invention relates to the lifting, supporting and moving of loads.

Often it is required to lift, and move, heavy loads under circumstances in which it is dilicult to insert lifting devices, such as jacks, and/or wheels, beneath the load. Whilst it may -be possible to lift the load by mobile crane, access to the load may be restricted, and the combined mobile crane and load may be of such an overall size that movement of the crane and load is extremely diicult.

According to the invention in one aspect a method of moving a load comprises positioning over the load a gas-retaining envelope adapted to envelop the load while presenting an open mouth towards the surface on which the load is supported, attaching the load to the envelope and introducing gas into the envelope to raise the pressure therein sufiiciently to take at least a major part of the weight of' the load so that it may be moved more readily.

According to the invention in another aspect there is provided apparatus for moving a load comprising a gasretaining envelope adapted to be positioned over a load so `as to envelop it while presenting an open mouth to- Wards the surface on which the load is supported, means for attaching the load to a part of said envelope and means for introducing into said envelope gas at sucient pressure to raise at least the part of said envelope to which the load is attached so as to take at least a major part of the weight of said load so that the load may be more easily moved.

The envelope may be flexible, at least in part, and may be inflated by the gas introduced into it.

In one form the envelope is of double-walled exible construction so that it may be inflated between the walls to erect it.

Moreover the envelope may be provided Vwith means for setting up a curtain of moving gas flowing from at least a part of the periphery of the envelope towards the surface over which the apparatus is operating so as to assist in the retention of a pressurised'cushion of gas within the envelope if and when the periphery thereof leaves the said surface. Such means may comprise simple outlet means suitably located and distributed around the periphery of the envelope and positioned so as to direct escaping gas downwardly and preferably somewhat inwardly from the lower edge towardsV the ground or other surface.

The invention will be readily understood by the following description of certain embodiments of the invention in conjunction with the accompanying drawings, in which:

'FIGURE 1 is a diagrammatic vertical cross-section through one embodiment,

-FIGURE 2 is a similar cross-section through another embodiment, v

FIGURE 3 is a similar cross-section through a further embodiment,

FIGURE 4 is a plan view of the embodiment illustrated in FIGURE 3,

FIGURE 5 is a vertical cross-section through the lower part of an envelope as illustrated in FIGURE 1 illustrating a modiiication thereof, FIGURE 6 is a further vertical cross-section through the lower part of an envelope as illustrated in FIGURE l illustrating Aa further modification thereof,

nesses of flexible material.

.compressor 11.

3,248,086 Patented pr. 26, 1966 ice FIGURE 7 is a cross-section on the line A-A of FIG- URE 2, illustrating one form of construction,

FIGURE 8 is similar cross-section to that of FIGURE 7 illustrating a further form of construction,

FIGURE 9 is another cross-section similar to that of FIGURE 7, illustrating yet another form of construction,

FIGURE 10 is a further cross-section similar to that of FIGURE 7, illustrating yet a further form of construction,

'FIGURES 11, 12 and 13 are diagrammatical cross-sections similar to that of FIGURE 1, illustrating various ways of -using the formof construction illustrated in FIGURE 10, and

FIGURE 14 illustrates a modification of the top part of an envelope as illustrated in FIGURE 1.

In FIGURE 1 the gas-retaining envelope 10 is in the form of a single sheet of flexible material, so shaped that when air from a compressor 11 is pumped in beneath the envelope, it is .inflated and assumes a hollow shape as shown. The envelope is positioned over the load 12 in an uninated condition, the load 12 being attached to load attachment means 13 by means of lropes 14. When air is pumped in beneath the envelope by the compressor 11 the envelope is inflated, a cushion of pressurised air being formed. When fully inflated, the load is lifted clear of the surface. Further air supplied beneath the envelope will cause the bottom edge 15 of the envelope also to lift slightly for at least part of its periphery, excess air escaping beneath t-he periphery.

When the load is clear of the surface the whole, that is envelope and load, can readily be moved. To facilitate this movement, the compressor 11 can be mobile, or can be connected to the envelope 10 by a flexible pipe 16.

To reduce the load concentration on the envelope a member 17, or several of such members, can be provided. The member can be of rigid or flexible construction.

The sheet of liexible material can be a single layer of material or of several layers which may be bonded together. Each layer, or any or all of the layers e'where several layers are used, can be in the form of a fabric impregapart. Air is supplied to the space between the two sheets I 20 and 21 and also to the interior of the envelope, by the The operation of this embodiment is very similar to that of FIGURE 1, the main difference being that the envelope itself is erected into its final shape bythe supply of air to the space between the two thickspace and then beneath the envelope or it can lbe fed simultaneously -to both places. Excess air escapes beneath the periphery of the envelope as before. v

FIGURE 3 illustrates a further embodiment in which an air curtain is formed at the bottom edge of the gasretaining envelope. The construction is substantially the same as in FIGURE 2, the hollow inflatable envelope 10 being inflated by air from the compressor 11. The load 12 is attached to the load attachment means 13 as before. In this example, however, a separate section or duct 25 is formed at the bottom edge of ,the envelope 10. The bottom surface of the duct 25 is provided with a continuous port 26. Air is -fed from the cornpressor 11 to the duct 25 and issues from the port 26 in a downwards and inwards direction to form a curtain of moving air 27. In operation, the envelope 10 may rst be inated and then air supplied to the duct 25, or, alternatively, air may be supplied to the duct 25 at the same time as the envelope is inflated. In either case,

Air can be fed rst to this issues from the curtain forming port 26 initially in a downwards and inwards direction, it is deflected by the cushion pressure round and outwards as shown.

The use of an air curtain to seal the gap between the bottom of the gas-retaining envelope and the surface, as shown in FIGURE 3, provides either a clearance similar to that provided in FIGURES 1 and 2 with a smaller air flow requirement, or an increased clearance lfor the same air flow.

FIGURE 4 illustrates a plan view of the embodiment illustrated in FIGURE 3, although it will be appreciated that the plan views of the embodiments illustrated in FIGURES 1 and 2 will lbe very similar. In the example shown, the plan form is circular, but obviously this plan form can be varied depending upon the actual construction of the envelope.

An air curtain may also be used in conjunction with the embodiment shown in FIGURE 1, by providing a duct having a port or ports at a suitable position. For example, a duct 30 may be formed at the bottom edge alternative, as illustrated in FIGURE 14, a rem-otelyv of the envelope 10, as illustrated in FIGURE 5. Alternatively a duct 31 may be positioned some distance up inside the envelope as in FIGURE 6, the bottom edge 32 of the envelope being of re-entrant form to direct the air forming the curtain initially inwards.

The construct-ion of the envelope illustrated in FIG- URES 2 and 3 can vary. FIGURES 7, 8 and 9 illustrate variations in the construction of the envelope illustrated in FIGURE 2, although similar variations can be used forthe envelope illustrated in FIGURE 3.

In FIGURE 7, the envelope is formed of two sheets of material andV 41 connected together by means of members 42. The members 42 can be in the form of Webs which can subdiv-ide the space between the sheets 40 and 41 into separate air-tight chambers. Alternatively, the members 42 can be in the form of perforated webs or cords.

FIGURE 8 illustrates a construction in the form o individual tubes 45 joined together, side by side. An alternative use of tubes is illustrated in FIGURE 9 where the tubes 48 are spaced apart and connected by a flexible sheet 49. The construction of FIGURE 9 would resemble a large umbrella, the tubes 48 forming the ribs and the sheet 49 the covering.

A further form of construction is illustrated in FIG- -URE l0. `The envelope comprises a sheet of flexible -material 50 stiifened or supported by members 51. The members 51 may all intersect at the top of the envelope as in FIGURE 1l, or may pass over the load from'one side to the other, substantially parallel, 'as in FIGURE 12. A further alternative is for the members 51 to be joined together at their ends, as in FIGURE 13. The envelope can 4be made in sections which are afterwards joined together. To reduce the escape of air beneath the bottom edge of the envelope, and-to improve the sealing between the bottom edge and the surface, a thin very flexible skirt member 52 can be attached round the bottom edge of the envelope, as illustrated in FIG- URE 13.

Load lifting apparatus as described above is particularly useful for lifting machines in a factory. lIn such cases it is often difficult to insert lifting devices and/ or moving devices beneath the machine, and access is limited. Furfther, when the load is lifted there are no concentrated loads on the ground as occurs with mobile cranes or trolleys. Apparatus as described above can readily be positioned over the machine and attached to it. In many cases, a separate compressor is not required, connection being made to an existing pressurised air supply in the factory. l

The apparatus may be arranlgedrso that the load iS lifted clear of the surface when the envelope is fully inflated, the cushion of air then lifting the inilated en-` velope, with the suspended load, clear of the surface.`

Alternatively, the apparatus -may be arranged so that when the envelope is fully inflated the load is still in contact with the surface, the cushion lifting the inflated envelope and the load clear of the surface. As a further controlled hoist 55 can be provided to lift the load clear of the surface once the gas-retaining envelope is inflated. The hoist, conveniently, is driven by means of an electric or pneumatic motor 56, the supply 57 for which can `be fed throug-h the top of the envelope in an air-tight manner.

The air can, of course, be-supplied at any position,` Air can be supplied,`

not only near the bottom edge. for example, at the top of the envelope as indicated by the dotted lines 58 in FIGURE 1.

Transparent panels may `be provided, or the entire structure can be of transparent material.

I claim:

1. Apparatus for moving a load which is normally supported on a surface comprising a gas-retaining envelope of flexible material adapted to be positioned over the load so as to envelop it While presenting an open mouth towards the surface on which the load is supported, said envelope comprising two sheets of material spaced apart to define a closed space and cooperating with said surface to form a cushion space wherein a gaseous pressure may be maintained, means for detachably connecting the load to a part of said envelope internal-ly thereof, means for introducing into said cushion space gas at sufficient pressure to inflate said envelope and to raise at least the part of said envel-ope to which the load is connected relative to the surface sutliciently to take a major part of the weight of said load off said surface so that the load may be more easily moved,1 and means for supplying gas under pressure to said` closed space.

2. Apparatus as claimed in claim 1 wherein the two` the load so as to envelop it while presenting an openy mouth towards the surface on which the load is supported, said envelope cooperating with said surface to form a cushion space `wherein a gaseous pressure may be maintained, means for detachably connecting the load to a part of said envelope internally thereof, means for introducing into said cushion space gas at a suflcient pressure to raise the envelope, and the load, clear of the said surface, and means for causing a gas to issue:

from the lower edge of the envelope to form at least one curta-in of moving gas which flows acrossthegap between lthe lower edge of the envelope and the said surface, the

curtain of moving gas assisting in retaining the gas inside the cushion space.

I5. Apparatus as claimed in claim 4 wherein the curtain Vof moving gas serves at least in part as the means for introducing the gas into the cushion space.

6. Apparatus as claimed in claim 4 wherein the means for causing a Vgas to issue from the 'lower edge of the envelope comprises a duct extending round the lower edge of the envelope, and at least one port formed in the lbottom of the duct.

v (References on following page) References Cited bythe Examiner UNITED STATES PATENTS 6 OTHER REFERENCES Design News, M-ay 23, 1960, pages 6 and 7, Ground Cushion Vehicle, Ba-lances With Single Engine. Y

Ritter et al. 244-117 Blair et al 244-117 X Murri.

Wade.

Cushman.

Bain et al. 244-117 Mackie.

5 WILLIAM FELDMAN, Primary Examiner.

PHILIP ARNOLD, Examiner.

R. M. WOHDFARTH, O. M. SIMPSON,

, Assistant Examiners. 

1. APPARATUS FOR MOVING A LOAD WHICH IS NORMALLY SUPPORTED ON A SURFACE COMPRISING A GAS-RETAINING ENVELOPE OF FLEXIBLE MATERIAL ADAPTED TO BE POSITIONED OVER THE LOAD SO AS TO ENVELOP IT WHILE PRESENTING AN OPEN MOUTH TOWARDS THE SURFACE ON WHICH THE LOAD IS SUPPORTED, SAID ENVELOPE COMPRISING TWO SHEETS OF MATERIAL SPACED APART TO DEFINE A CLOSED SPACE AND COOPERATING WITH SAID SURFACE TO FORM A CUSHION SPACE WHEREIN A GASEOUS PRESSURE MAY BE MAINTAINED, MEANS FOR DETACHABLY CONNECTING THE LOAD TO A PART OF SAID ENVELOPE INTERNALLY THEREOF, MEANS FOR INTRODUCING INTO SAID CUSHION SPACE GAS AT SUFFICIENT PRESSURE TO INFLATE SAID ENVELOPE AND TO RAISE AT LEAST THE PART OF SAID ENVELOPE TO WHICH THE LOAD IS CONNECTED RELATIVE TO THE SURFACE SUFFICIENTLY TO TAKE A MAJOR PART OF THE WEIGHT OF SAID LOAD OFF SAID SURFACE SO THAT THE LOAD MAY BE MORE EASILY MOVED, AND MEANS FOR SUPPLYING GAS UNGER PRESSURE TO SAID CLOSED SPACE. 